Berlin - Borussia Dortmund's unbeaten start to 2016 comes under threat with a visit to third-place Bayer Leverkusen in the Bundesliga sandwiched between Europa League games against Porto.
Dortmund, with four wins and one draw in five games across all competitions this year, hosts Porto on Thursday, visits Leverkusen on Sunday, then travels to Portugal for the second leg of its Europa League second-round tie.
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Despite Dortmund's impressive form in the Bundesliga, the side already has more points (48) than all last season (46) it trails Bayern Munich by eight points with little chance of catching the league leaders barring a spectacular and unlikely collapse from Pep Guardiola's side.
Dortmund has more chance to claim honors in the Europa League, meaning Thomas Tuchel is likely to prioritize the meetings with Porto over Leverkusen, which is 13 points behind in the league.
Bayern, which has dropped points only three times this season, hosts promoted Darmstadt on Saturday, when Borussia Moenchengladbach hosts Cologne for the Rhine derby.
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Leverkusen also faces Portuguese opposition either side of its game with Dortmund. Roger Schmidt's side was to visit Sporting Lisbon on Thursday with the return the following week.
But Leverkusen's league predicament is more pressing with Hertha Berlin level on points, Schalke and Mainz just two points behind and 'Gladbach three behind.
Leverkusen hasn't beaten Dortmund at home since a 2-1 win in 2007 but the side appears to be finding form at just the right time. Last weekend's 2-1 win at Darmstadt stretched its unbeaten run in the league to six games for the first time this season.
Club top-scorer Pierre-Emerick Aubameyang is likely to be back for Dortmund after sitting out last weekend.
Bayern will be hoping to avoid any further injuries against Darmstadt before its trip to Turin for the first leg of its Champions League Round of 16 tie against Juventus on Tuesday.
Bayern defenders Jerome Boateng, Javi Martinez and Holger Badstuber are all ruled out and emergency signing Serdar Tasci is yet to play following a head injury suffered in his first training session.
Bayern's makeshift back-four of Philipp Lahm, Joshua Kimmich, David Alaba and Juan Bernat have another chance to play together before the all-important Juventus clash.
Darmstadt, back in the Bundesliga after 33 years, has little hope of upsetting the home side, especially with five players ruled out through suspension.
Moenchengladbach is yet to rediscover the form it displayed when Andre Schubert took over and matched a Bundesliga record by starting with six wins. Three defeats and one win in 2016 have seen the side slip to seventh.
Cologne, unbeaten in three games, could draw level with an away win Saturday.
"It's always something special." Cologne captain Matthias Lehmann said of the derby. "We want to deliver a good game Saturday and keep the momentum going."
Hertha Berlin is another side yet to click into gear in 2016. Pal Dardai's side is four league games without a win for the first time this season and last weekend's 2-0 defeat in Stuttgart saw it surrender third-place on goal difference to Leverkusen.
"Every team has a phase in the season in which it doesn't flow so well. Perhaps we're having this phase now," said Dardai, who identified Saturday's home game against Wolfsburg as a "key game."
Wolfsburg ended its own poor run, seven games without a win, with a 2-0 victory over Ingolstadt last weekend but coach Dieter Hecking has warned against complacency.
"Whoever thinks they can relax now is on the wrong path," Hecking said.
Wolfsburg conceded two late goals to squander a 3-0 lead over Gent in the Champions League on Wednesday. The game ended 3-2.